材料期刊网

PHASE COMPONENT AND CURIE TEMPERATURE OF Nd_4(Fe_(1-x)Cr_x)_(77.5)B_(18.5)ALLOYS

B.X. Gu , J.R. Zhang , B.G. Shen and H Wang (Department of Physics , Nanjing University , Nanjing 210093 , China)(State Key Lab. of Magnetism , Institute of Physics , Chinese Academy of Sciences , Beijing 100080 , China)(Department of Physics , Southeastern University , Nanjing 210008 , China)

金属学报(英文版)

The phase component and Curie tempemture of Nd4(Fe1-xCrx)77.5B18.5 (0 0.1. The magnetic measurement shows that Curie temperutures of Fe3B and Nd2Fe14B phases decrease with increasing Cr content. The influence of the substitution of Cr for Fe was discussed.

关键词: Nd_4(Fe_(1-x)Cr_x)_(77.5)B_(18.5)alloy , null , null

EFFECT OF SPECIMEN SIZE ON J_R RESISTANCE CURVE

H.P. Chen and Z.J. Deng (State Key Lab. for Mechanical Behavior of Materials , Xi'an Jiaotong University , Xi'an 710049 , China)

金属学报(英文版)

The effect of specimen thinkness on JR resistance curve has been investigated using low and middle strength steels. As the J dominance regime is reached, the initial J-integral values, J(i), are definite even if the elastic component Ji(e) and plastic component Ji(p)vary with the thinkness of specimen. The wider the specimen width, the larger the Ji(e)/Ji and the smaller the Ji(p)/Ji. The crack propagation resistance, dJR/da and dJp/da, decreases, while dJe/da increases linearly with increasing specimen thinness.Based on the above experimental results, an empirical formula dJ/da = α+β. B is given, which can be used to evaluate the safety of practical structural components.A modified J-integral is presented, upon which a new view is Put forward that the increase in crack growth resistance is induced mainly by the increase in the plastic J-integral component with the crack propagation,

关键词: : fracture mechanics , null , null , null

关于动态钝化线方程与J-R法确定JId的讨论

杨卓青 , 刘瑞堂 , 周志方 , 尹建成

机械工程材料 doi:10.3969/j.issn.1000-3738.2006.03.006

在摆锤式示波冲击试验机上采用小角度冲击方法测试了某船用低合金钢的动态弹塑性断裂韧度JId.针对多试样J-R阻力曲线法因钝化线的不易确定性常造成测试结果JId误差较大的情况,考虑了加载速率对塑性流变应力的影响,给出了一新的动载条件下的钝化线方程:J=2NK(0.5εF)n△a.在J-R阻力曲线法测定材料的JId时,用该方程可得到与小角度冲击方法相一致的测试结果.

关键词: 动态钝化线 , 小角度冲击法 , J-R阻力曲线法 , 动态弹塑性断裂韧度JId

Jian ZHANG/Langhong Lou

材料科学技术（英）

关键词:

Spin waves in a four-sublattice Heisenberg ferrimagnet or ferromagnet with different exchange constants (J(ab)=J(cd)not equal J(bc)=J(da))

Physical Review B

The Hamiltonian for a four-sublattice Heisenberg ferrimagnet or ferromagnet with different exchange constants (J(ab) = J(cd) not equal J(bc) = J(da)) was established. An extended Bogoliubov transformation was developed by solving an equation group, consisting of 20 equations and 20 unknowns. The procedure for solving the equation group was carried out by introducing a simple way of reducing the numbers of the equations and the unknowns. The spin-wave spectra in the present system have been determined by performing the standard Holstein-Primakoff transformation and the Bogoliubov one. It has been found that the spin-wave spectra of the present system depend on the exchange constants and that the degeneracy of the spin-wave spectra remains. The results for a special case (J(ab) = J(bc)) i.e., an antiferromagnet are discussed briefly. The spin-wave spectra of the four-sublattice Heisenberg antiferromagnet are found to be degenerative also and they are linear in k for small k.

关键词: model

高分子专利j

高分子材料科学与工程

专利名称：具有改进的抗冲击性、尺寸稳定性和吹塑成形性能的热塑性ABS树脂组合物专利申请号：CN200580040787．3公开号：CN101065413申请日：2005．03．31公开日：2007．10．31申请人j韩国第一毛织株式会社根据本发明的热塑性ABS树脂组合物包括：（a）2

关键词: 专利名称 , 高分子 , 树脂组合物 , 专利申请号 , 尺寸稳定性 , 抗冲击性 , 株式会社 , 成形性能

Study on the Relationship Between J-Integral and COD

Y.G. Cao , X.Y. Sun

金属学报(英文版)

J-integral and crack opening displacement δ(COD) were important parameters for characterization of fractures in engineering materials. The relationship between J-integral and COD has been investigated for a long time and was enerally represented as J = m σyδ, where σy is the yield strength and m is a function of specimen geometry and material properties. To determine the value of m, extensive studies and experiments have been performed. The method that used the fracture-surface topography analysis (FRASTA) for determining J-integral from fracture surfaces of materials was introduced. On the basis of the relationship between COD and fracture surface average profile, the relationship between J-integral and COD was deduced and compared with the generally used equation. The method was experimentally confirmed to be able to provide a new way to determine the relationship between J-integral and COD.

关键词: FRASTA , null , null

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

浅析CTOD和J积分的关系

周峰峦 , 郭震

物理测试 doi:10.13228/j.boyuan.issn1001-0777.20160084

推导了CTOD和J积分的关系,并且从试验角度利用三点弯曲试样进行CTOD试验,根据ASTM E1820对GB/T 21143-2014中公式34进行了评价,研究表明,在小屈服范围内,采用裂纹嘴张开位移可以同时得到CTOD和J积分,从而可以简化J积分的试验装置.

关键词: J积分 , CTOD , 小屈服

悬臂弯曲方法测定J_(Ic)和J_(Iscc)的探讨

null , null

金属学报

在工程上,经常由于应力腐蚀开裂和氢脆引起中强度钢结构件发生滞后破坏。这类脆断往往从结构件中预先存在的疲劳或焊接裂纹处开始,因此,运用传统的光滑试样的检验方法不能反映这类破坏的特点。 本文将弹塑性断裂力学中的J积分概念用于滞后破坏的研究,提出用带预制疲劳裂纹的悬臂弯曲试样测定J积分的临界值J_(Ic)和应力腐蚀开裂阈值J_(Iscc)的方法。测定了40CrNiMo钢的J_(Ic)值及其在硫化氢水溶液中的J_(Iscc)值。通过和三点弯曲方法测定的J_(Ic)值的对比,以及和满足线弹性条件时直接测定的应力强度因子K_I值的对比,说明这种方法的可靠性。最后,对悬臂弯曲方法的特点进行了讨论。

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